Stoker



Dec. 5, 1939. c. J. SURDY ET AL STOKER Filed July 2'7, 193'? 3 Sheets-Sheet 1 WW owm a T57 N N. 2 my mm mm YIIA Dec. 5, 1939. c. J. SURDY ET AL STOKER Filed July 27,. 1937 3 Sheets-Sheet 2 INVENTORS C HAIELES J'fiURDY BYE. ARC/7'51? TOR/V5,?

kZ/Q WM AT ORNEY5 Patented Dec. 5, 1939 UNITED STATES PATENT OFFICE STOKER Application July 27, 1937, Serial No. 155,903

6 Claims.

This invention, which relates to stokers, has for its principal object the provision of new and improved means for supplying fuel over the firebed .of a furnace.

It is a further object of this invention to improve means for controlling fuel distribution over the firebed a's delivered thereover by astoker having a pair of fuel distributors, each of which is capable of spreading fuel over the entire firebed.

Another object of this invention is to provide means operable by pressure of fluid in a boiler for controlling fuel distribution by a stoker of the type specified.

A still further object of the present invention resides in provision of means for controlling operation of a stoker having a pair of fuel delivery conveyors and distributors, each of which is adapted to deliver and spread fuel evenly over the firebed, such means arranged to interrupt operation of a fuel delivery conveyor and distributor upon increase of pressure fluid in the boiler beyond a predetermined point.

Conversely, this means also functions to initiate operation of such fuel delivery conveyor and distributor upon decrease of pressure fluid in the boiler below a predetermined point, and accordingly, this constitutes another object of our invention.

Other objects, and the advantages to be derived therefrom. will become apparent as the following description of the invention is read in connection with the accompanying drawings, showing the invention as applied to a locomotive and in which drawings:

Figure l is a vertical medial section through adjacent portions of a locomotive and tender with the stoker in similar sections, portions of which have been broken away;

Figure 2 is a plan view of the stoker structure shown in Figure 1 with the locomotive boiler in section;

Figure 3 is an end elevation of the locomotive as viewed along line 33 in Figure 1 with portions of the stoker broken away;

Figure 4 is a sectional view taken along the line 44 of Figure 3; and

Figure 5 is a fragmentary sectional view on the line 55 of Fig. 3.

In these drawings, L indicates a locomotive, T the tender and C a coupling therebetween. The locomotive L comprises a frame III which is carried upon the running gear I l in known manner. Above the frame I0 is a boiler 12 which includes a firebox l3 defined by the backwall l4, sidewalls i I5, I6 and the throat or back flue sheet ll.

plane passing through the locomotive.

Tubes l8 extend from the upper portion of the backwall l4 downwardly to the front water leg l9 and support refractory brick to form a fire arch 2|. Grates 22 are utilizedfor supporting a firebed within the firebox l3. 5

Rearward of the backwall i4 and above the level of the grates 22 is a cab 23 having a deck 24 above which deck the backwall I4 is provided with an aperture 25 disposed along the vertical medial The aperl0 ture 25 is utilized for gaining access to the interior of the'firebox l3 and normally is closed by the doors 26.

A stoker S delivers fuel over the firebed in the firebox l3 and comprises a fuel receiving conveyor 5 21 disposed on the tender T and a fuel delivery conveyor 28 carried by the locomotive L. While the stoker herein illustrated is similar in certain respects to stoking mechanism of known construction, its mode of operation differs from 20 former devices and produces new and improved results not possible heretofore.

In stokers, especially those used to fire locomotives, a steam or other pressure fluid jet is utilized for. projecting fuel over the' firebed. These stokers usually employ a single fuel delivery and distributing member adapted to spread fuel uniformly over the firebed. It has been found that a uniform distribution of 'fuel with an approximately equal segregation of fine and 3 coarse fuel over the firebed can beattained with the use of pressure fluid jets provided that the jet pressures are maintained within a predetermined range. If the jet pressure is low, a preponderant amount of lump coal will be spread over the rearward portion of the firebed, and if a high jet is used, the greater percentage of fine fuel is deposited at the forward end of the firebed.

According to the present invention, we provide a stoker having a pair of fuel feeding units 29,

each capable of spreading fuel evenly over the firebed and so arranged that only the primary unit 29 delivers and spreads fuel over the entire firebed when the locomotive is under a light load. When steam consumption of the locomotive increases for any reason, the auxiliary unit 30 supplements the function of the primary unit 29 and also supplies fuel over the firebed. By this arrangement, the maximum amount of fuel to be handled by each unit 29, 30 will not exceed the amount which can be projected by a fluid jet and under a pressure within a range best suited to spread evenly an approximately equal segregation of fine and lump fuel.

The fuel receiving conveyor 21 includes a trough conduit 3| having a screw 32 therein arranged to urge fuel against a crv'her 33 and then deliver the crushed fuel into a chamber or hopper 34 which is disposed on the locomotive and forms a portion of the fuel delivery conveyor 28. At its forward end, the trough conduit 3| is provided with a ball member 35 fitting into a bore 35 of the hopper 34 to form a universal joint 31 between the conveyors 21 and 28. Rollers 38 afford flexible support for the conveyor 21 on the tender T. The screw 32 is operatively connected to shafting 39 by means of gears 45.

The primary and auxiliary feed units 29, 35 form a part of the conveyor 28 and include a tubular casing 4|, 42 each seated upon the hopper 34 and housing a fuel elevating screw 43, 44, respectively. Each screw 43, 44 extends into the hopper 34 and is arranged to receive fuel in amounts as apportioned by the manually controlled divider 45. The screws 43, 44 diverge laterally as they extend upwardly along the backwall I 4 and each feeds through a respective opening 45, 41' in such backwall, one at each side of the aperture 25. Above said diverging tubular casing 4|, 42 is a forwardly curved elbow conduit 48, 49 for directing fuel into a distributor member 55, 5| passing through an opening 45, 41 respectively. Each elbow conduit 48, 49 carries a respective jet member 52, 53, the jet member 52 is arranged toproiect fuel forwardly over the flrebed as delivered thereto by the screw 43, while the jet member 53 serves to project the fuel delivered thereto by the screw 44. As shown in Figure 2, the distributors 55, 5| converge toward each other in forward extent and are so arranged and related with a respective jet member 52, 53 that each distributor 55, 5| spreads fuel evenly over the firebed.

The hopper 34 is provided with a bore 54 which houses and serves to maintain the gearing for operating the screws 32, 43 and 44. At one side of the hopper 34 is an engine: 55 which operates a shaft 55 having mounted thereon the worm gears 51 and 58, operatively associated with the elevating screws 43 and 44, respectively, in a manner well known in the art, as in Patent No. 1,828,116, granted October 20, 1931. The worm gear 51 is made fast to the shaft 55 while the worm gear 58 is loosely mounted thereon but arranged to be keyed to said shaft 55 through the intermediacy of a clutch 59.

Power is also supplied from the engine 55 for operating a shaft 55 which is arranged to drive, at proper rates of speed, the conveyor screw 32 through shafting 39 and the gears 45. For this purpose a worm gear 5| is loosely mounted on the shaft 55 and it meshes a worm wheel 52 which is keyed to the shaft 55. The worm gear 5| has secured thereto a gear 53 meshing with a gear 54 on the countershaft 55 which is journaled in the gear case 9. A gear 55 carried by the countershaft 55 meshes with a gear 51 loosely mounted on the shaft 55, said last named gear 51 arranged to be keyed to the shaft 55 by means of a clutch 58. Movement of the clutches 59 and 58 is accomplished through shifters 59 and 15, respectively, each of which is mounted on a rod 1 I.

When the locomotive L is being operated under conditions which consume a moderate amount of steam, only the primary feed unit 29 functions to supply fuel over the entire flrebed, while the auxiliary feed unit 35 supplies fuel, in addition to that delivered by the primary feed unit 29, only when steam consumption of the locomotive exfirebox by both feed units 29, 35 when the pressure of steam within the locomotive boiler is reduced below a predetermined point. This means also functions to interrupt delivery of fuel by the auxiliary feed unit 35 when the pressure of steam within the boiler |2 reaches a predetermined point.

Secured to the backwall 4 is a valve V comprising a casing 12 within which is mounted a piston valve 13. Steam is conducted to the valve casing 12 by a 'pipe 14 leading from the main supply line 15. On one side of the piston valve 13 is a spring 15, the tension of which may be adjusted by the hand nut I'I so that the piston valve I3 may be balanced, in the position shown in Figure 4, against the pressure of steam on the upper side of the valve 13 as supplied thereto by the pipe I8. It is to be understood that when the valve 55 is balanced in the position shown in Figure 4, the pressure of steam within the boiler I2 is being maintained at the required point by operation of the primary feed unit 29 only,

The piston valve 13, when in the position shown in Figure 4, closes off the port 19 from which lead pipes 85 and 8|; the pipe 85 supplies pressure fluid to the auxiliary jet member 53 while the pipe 8| supplies steam to a cylinder 82 in which is disposed a piston 83 carrying the clutch operating rod H. A spring 84 maintains the piston 83 and the rod H and associated clutches 59, 58 in the position shown in Figure 3 during absence of steam in pipe 8|. The primary jet member 52 receives pressure fluid (steam) direct from the main supply line by means of a pipe 85.

Assuming that the locomotive L is operating under a light load, only the feed unit 29 will be operative to deliver fuel over the flrebed, and the piston valve 13 will be balanced in the piston shown in Figure 4. Under these conditions, the clutch 59 will be disengaged from the worm gear 58 for interrupting operation of the elevating screw 44, and piston valve I3 cuts off flow of pressure fluid to the jet member 53. Also, the clutch 58 engages gear 51 for driving the worm gearing 5|, 52 at a slower rate of speed which results in less fuel being fed by the oonveyor'screw 32 into the hopper 34.

When the operating rate of the locomotive L is increased, or the rate of steam consumption otherwise increased, the pressure of steam in the boiler l2 will be reduced. As a consequence, the pressure reacting on the upper side of piston valve I3 will be lowered correspondingly whereby the spring 15 will move the valve 13 upwardly to establish communication between pipe 14 and port 19. This admits steam to auxiliary jet member 53 through pipe 85, while pipe 8| admits steam into the cylinder 82 for moving piston 83 toward the right. As the piston 83 moves thus, clutch 58 disengages the gear 51 and drives the worm gearing 5|, 52 in a direct manner to assure a higher delivery rate of fuel to the hopper 34. Movement of piston 83 against the tension of spring 84 also causes the clutch 59 to engage worm gear 58 for operating the elevating screw 44. In this manner, the auxiliary feed unit 35 will supplement the primary feed unit 29 in its delivery and distribution of fuel over the flrebed.

Upon reaching the predetermined pressure of steam in the boiler i2, it will be apparent that the valve V will function to interrupt operation of the auxiliary feed unit 30 and to control the operation of the conveyor 21.

From the foregoing, those familiar with the art will readily understand that the stated aims and objects of this invention have been attained by a novel stoker which is highly eflicient in operation.

While the invention has been described in connection with a locomotive, it is to be understood that it is not limited in use to this field alone and that certain features of the present invention are of general application,

We claim:

1. In a fluid boiler having a firebox and a grate for supporting a flrebed, a stoker for delivering fuel into said firebox comprising a pair of fuel feeding units, each unit arranged to spread fuel over the entire flrebed, a conveyor for urging fuel toward each of said fuel feeding units, driving mechanism for operating said fuel feeding units and said conveyor at desired rates of speed, means responsive to pressure of fluid in said boiler for interrupting operation of one of said fuel feeding units, and added means cooperating with the first named means for reducing the speed of said conveyor without substantial change of speed of the other of said fuel feeding units.

2. In a fluid boiler having a firebox and a grate for supporting a flrebed, a stoker for delivering fuel into said firebox comprising a pair of fuel feeding units, each of said fuel feeding units including a distributor member arranged to spread fuel over the entire flrebed, a conveyor for urging fuel toward each of said fuel feeding units, driving mechanism for operating said plurality of fuel feeding units and said conveyor at desired rates of speed, means responsive to pressure of fluid in said boiler for interrupting operation of one of said fuel feeding units and its respective distributor member, and added means cooperating with the first named means for reducing the speed of said conveyor without substantial change of speed of the other of said fuel feeding units.

3. In a fluid boiler having a firebox and a grate for supporting a flrebed, a stoker for delivering fuel into said firebox comprising a pair of fuel feeding units, each of said fuel feeding units including a fuel conveyor and a fuel distributor member receiving fuel from a respective conveyor and arranged to spread fuel over the entire flrebed, a. conveyor for urging fuel toward each of said fuel feeding units, driving mechanism for operating said fuel feeding units and said conveyor at desired rates of speed, means responsive to increase in pressure of fluid in said boiler above a predetermined point for interrupting operation of one of said fuel feeding units and its respective distributor member, and added means -cooperating with the first named means for reducing the speed of said conveyor without substantial change of speed of the other of the fuel feeding units.

4. In a fluid boiler having a firebox, a stoker for delivering fuel into said firebox comprising a plurality of fuel feeding units, each of said fuel feeding units including a fuel distributor member arranged to spread fuel over the entire flrebed, a conveyor for urging fuel toward each of said fuel feeding units, driving mechanism for operating the plurality of fuel feeding units and said conveyor at desired rates of speed, means responsive to the pressure of fluid in said boiler for interrupting operation of one of said fuel feeding units, and added means cooperating with the first named means for reducing the speed of said conveyor without substantial change of speed of the remainder of the fuel feeding units.

5. In a fluid boiler having a firebox, a stoker for delivering fuel into said firebox comprising a plurality of fuel feeding units, each of said fuel feeding units including a fuel distributor member arranged to spread fuel over the entire flrebed, each of said fuel feeding units including a fuel conveyor and a fuel distributor member receiving fuel from a respective conveyor and arranged to deliver the fuel into the firebox, a conveyor for urging fuel toward each of said fuel feeding units, driving mechanism for operating the plurality of fuel feeding units and said conveyor at desired rates of speed, means responsive to an increase in pressure of fluid in said boiler above a predetermined point for interrupting operation of one of said fuel feeding units, and added -means cooperating with the first named means for reducing the speed of said conveyor without substantial change of speed of the remainder of the fuel feeding units.

6. In a fluid boiler having a firebox and a grate for supporting a flrebed, a stoker for delivering fuel into said firebox comprising a plurality of fuel feeding units, each of said fuel feeding units including a distributor member arranged to spread fuel over the entire flrebed, a conveyor, mechanism for rendering said conveyor operative to supply fuel to said fuel feeding units at desired rates of feed, means for rendering the fuel feeding units operative to deliver into the firebox the fuel received from said conveyor, means responsive to pressure of fluid in said boiler for interrupting operation of one of said fuel feeding units, and added means cooperating with the second named means for reducing the rate of delivery of said conveyor without substantial change in the rate of delivery of the other of said fuel feeding units.

CHARLES J. SURDY.

E. ARCHER TURNER. 

